my ex and I split up 6 years ago, we have 2 kids together who are now 8 & 9, for the last 6 years we have been getting on good, having family days out and until last year being intimate on occasions. Oct 2022 he told me out of the blue that he has started to see someone, now this someone is someone I know and dont like, hes known her since school but I was told (when we were together) that she liked him or there was chemistry so I had a dislike for her then straightaway. Now it feels like to plaster has come off the wound again and cannot mentally deal with it at, I have told the ex she is not to be around on his weekends with kids until we have been to mediation, well he couldnt wait and I found out so i stopped contact, we've been to mediation and they now want to speak to the children and their views as they previously told me they didnt want to see her. Well tonight the kids after being at his this weekend, that they are happy to see him and her so this has sent me in a dark deep hole, he said at meditation its likely to be long term and they will move in together at sometime. Im in 2 minds whether to stop contact completely and move away or the kids live with him full time, i just dont know how to cope or deal with this? ive never had to deal with this in the past as hes been my only long term relationship and were engaged. Any advice?